Hipolito

(b. Nov. 21, 1849, Bringetofta, d. Nov. 17, 1925, Stockholm), began his career as an engineer at the Lesjöfors Ironworks and in 1882 became chief engineer at the Fagersta Ironworks. 1903-14 he was chief engineer at Jernkontoret.
He is probably best known today for the Brinell hardness test, a rapid, non-destructive means of determining the hardness of metals. The test is based on themeasurement of the impression left by a 10-millimetre-diameter hardened steel or carbide ball after it is pushed into the metal with a 3,000-kilogram load. The Brinell hardness number is obtained by dividing the load, in kilograms, by the spherical area of the indentation in square millimetres; this area is a function of the ball diameter and the depth of the indentation. With minor variations, his teststill remains in wide use.
But more important still was Brinell’s pioneering work concerning phase transformations in steel. While at Fagersta, Brinell made extensive studies of the internal composition of steel during cooling and heating. "Om ståls texturförändringar under uppvärmning och avkylning" ("About texture changes in steel during heating and cooling") was published in JernkonoretsAnnaler 1885. Using very primitive equipment, relying on his own eyes and experience, Brinell continued his research for many years and achieved results that "deeply affected the world’s industry." His discoveries about the control of the carbon containing phases still form the basis of our knowledge about the properties of steel.
 
"Few metallurgists have done so much towards the advancement ofmetallurgy as Mr Brinell and he richly deserves his world-wide reputation as a remarkably able investigator and successful steelworks manager."
(Albert Sauveur, 1863-1939, American metallurgist)
 

Nació el 21 de noviembre de 1849 en Bringetofta Smalond (Suecia). Destacado Ingeniero en la fabricación de acero. Educado en la Escuela Técnica Boras, dedicado al diseño en 1875 de una fábrica deherrajes. En 1885, da sus trabajos sobre la estructura química para el endurecimiento del acero, los cuales ocurrían en el calentamiento y enfriamiento. Muere el 17 de noviembre de 1925 en Estocolmo (Suecia).
The Brinell Hardness Test is the oldest method of hardness testing commonly used today. The Brinell test was invented in Sweden by Dr. Johan August Brinell in 1900. This test is often used todetermine the hardness of castings and forgings whose grain structure is too course for accurate Rockwell or Vickers testing. Almost all metals may be tested with the Brinell test by simply varying the ball size and test force. As long as the ball size to test force ratio remains constant, the results are considered accurate.
Results from the Brinell Hardness Test are used extensively in industryas a basis of acceptance of commercial shipments, and for quality control purposes generally. These result may correlate with metallic characteristics such as: ductility, tensile strength, wear resistance, etc.,
The Brinell Test is an indentation hardness test consisting of two steps. Step one, the indenter is brought in contact with the tests specimen perpendicular to the surface and thespecified test force is applied. The test force held for the specified time and then withdrawn. Step two, The diameter of the indentation is measured in at lest two directions perpendicular to each other. The Brinell hardness value is computed from the mean of the diameter measurements by the use of a mathematical formula designed for this purpose, or more frequently from a chart based on the formula.The complete ASTM E 10 Standard Test Method for Brinell Hardness of Metallic Materials may be obtained from ASTM International.

(. El 21 de noviembre de 1849, Bringetofta, d. El 17 de noviembre de 1925, Estocolmo), comenzó su carrera como un ingeniero en el Lesj ö fors la Fundición y en 1882 se hizo el ingeniero principal en la Fundición Fagersta. 1903-14 él era el ingeniero principal en...